Conductive agent composition and conductive agent dispersion for battery

Abstract

The present invention relates to a conductive agent composition, a conductive agent dispersion comprising the conductive agent composition, a method for preparing the conductive agent dispersion, the use of the conductive agent composition or the conductive agent dispersion in manufacturing an electrode, and an electrode. The conductive agent composition comprises carbon black and at least one material selected from the following materials: a carbon nanostructure, fragments of a carbon nanostructure, and fragmented multi-walled carbon nanotubes.

Description

Conductive agent compositions and conductive agent dispersions for battery applications TECHNICAL FIELD

[0001] The present invention relates to conductive agent compositions, conductive agent dispersions comprising the conductive agent compositions, methods of making the conductive agent dispersions, use of the conductive agent compositions or conductive agent dispersions for manufacturing electrodes, and electrodes, wherein the conductive agent compositions comprise carbon black and at least one material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures, and broken multi-walled carbon nanotubes. BACKGROUND

[0002] Lithium ion batteries are a common source of electrical energy for a wide range of applications from electronic devices to electric vehicles. Lithium ion batteries (LIBs) typically include negative and positive electrodes arranged to allow lithium ions and electrons to move into and out of the electrodes during charging and discharging. An electrolyte solution in contact with the electrodes provides a conductive medium in which the ions can move. To prevent direct reactions between the electrodes, ion-permeable separators are used to physically and electrically isolate the electrodes. During operation, electrical contact is made to each electrode, allowing electrons to flow through the device to provide electrical power, and lithium ions to move through the electrolyte from one electrode to the other.

[0003] In many cases, the negative electrode is constructed from graphite. The positive electrode typically includes a conductive substrate that supports a mixture having at least an active material, a binder, and a conductive additive, for example, applied as a paste. The electroactive material, such as a lithium transition metal oxide, is capable of receiving and releasing lithium ions. The binder, such as polyvinylidene fluoride (PVDF), is used to provide mechanical integrity and stability to the electrode. Since the electroactive material and binder often exhibit poor conductive properties or insulating properties, materials such as graphite and carbon black are often added to enhance the electrical conductivity of the electrode.

[0004] Some positive electrode materials used in lithium ion batteries, such as LFP, NCM, and NCA, can exhibit low electrical conductivity, for example, 10 -9 Siemens per centimeter (S / cm) - 10 -4 S / cm. To avoid battery failure, this performance can be enhanced by the addition of conductive additives, which function to form a conductive network between active material particles, thereby enhancing the electrical conductivity of the lithium ion battery electrode. Some materials with the potential to enhance electrical conductivity and avoid battery failure include conductive carbon black (CB), such as having a grape-like morphology, and carbon nanotubes (CNTs).

[0005] Since the conductive additives and binders typically do not participate in the electrochemical reactions that generate electrical energy, these materials can negatively affect certain performance characteristics of the battery (e.g., capacity and energy density) because they effectively reduce the amount of electroactive material that can be contained in the volume available for the positive electrode.

[0006] To build the conductive network, the amount of CB required is relatively high, typically exceeding 2 wt.%. Furthermore, volume expansion and contraction of the positive electrode can result in loss of contact between CB particles, leading to battery failure.

[0007] CNTs can be considered as an attractive material with the potential to reduce the amount of additives to be introduced into the positive electrode composition relative to the amount of CB. Some difficulties encountered in utilizing CNTs include limited dispersibility in some media and insufficient purity. It is believed that at least some of these problems are caused by strong van der Waals forces that occur between individual carbon nanotubes, resulting in their agglomeration into bundles or tangles. Such behavior can result in less than expected property enhancement and / or inconsistent performance. In some cases, techniques that can be used to debundle carbon nanotubes into individual, well-dispersed members can detrimentally affect the desired property enhancement relative to that expected when using pristine carbon nanotubes.

[0008] Often, the low dispersibility of CNTs is addressed by using an excess (i.e., more than the theoretical amount) of CNTs. However, this approach increases manufacturing costs, introduces impurities (e.g., iron and cobalt catalysts used to make CNTs), and can reduce battery capacity by reducing the volume of the battery available for electroactive materials.

[0009] Another difficulty is the concern for the environmental health and safety profile of individual carbon nanotubes due to their small size. Also, in the case of some commercial applications, the cost of manufacturing individual carbon nanotubes can be prohibitive.

[0010] To address these problems, a carbon nanostructure (CNS), which is a special type of multi-walled carbon nanotube, with a tangle and branched structure, has been proposed. Electrons conduct through the branched tubes that are covalently connected and penetrate the contact between the tubes at very low loadings. The combination of CNS with conventional CB and optionally CNTs can build a more efficient three-dimensional conductive network.

[0011] While the combination of CNS with CB and optionally CNTs used as conductive additives addresses the above problems and enhances the conductivity of lithium-ion battery electrodes, as the industry application of lithium-ion batteries expands, particularly more stringent performance requirements are placed on lithium-ion batteries.

[0012] There is still a need for a conductive additive that is capable of significantly improving the performance of lithium ion batteries, in particular the DCIR (direct current internal resistance) growth rate. In addition, the conductive additive should also improve the low temperature performance of the battery, for example the low temperature discharge capacity retention rate. SUMMARY

[0013] It is an object of the present invention to provide a conductive agent composition for electrodes, preferably for lithium ion battery electrodes, which is capable of improving the performance of lithium ion batteries, in particular the DCIR growth rate, and preferably improving the low temperature performance of the battery, for example the low temperature discharge capacity retention rate.

[0014] Thus, in a first aspect, the present invention provides a conductive agent composition comprising carbon black (CB) and at least one material selected from the group consisting of carbon nanostructures (CNS), fragments of carbon nanostructures and broken multi-walled carbon nanotubes, wherein the carbon black has a BET specific surface area of more than 200 m 2 / g, preferably 300 m 2 / g to 2000 m 2 / g, preferably 400 m 2 / g to 1800 m 2 / g, preferably 500 m 2 / g to 1600 m 2 / g, preferably 600 m 2 / g to 1400 m 2 / g, preferably 700 m 2 / g to 1000 m 2 / g, most preferably 800 m 2 / g to 900 m 2 / g.

[0015] In a second aspect, the present invention provides a conductive agent dispersion comprising the conductive agent composition according to the first aspect of the present invention and a solvent.

[0016] In a third aspect, the present invention provides a method of preparing a conductive agent dispersion according to the second aspect of the present invention, comprising combining the conductive agent composition, a solvent, and optionally a dispersant to form the dispersion.

[0017] In a fourth aspect, the present invention provides the use of a conductive agent composition according to the first aspect of the present invention or a conductive agent dispersion according to the second aspect of the present invention for the manufacture of an electrode.

[0018] In a fifth aspect, the present application provides an electrode, preferably for a lithium ion battery, comprising a current collector and an electrode active material layer, wherein the electrode active material layer comprises the electrically conductive agent composition according to the first aspect of the present application.

[0019] Finally, in a sixth aspect, the present application also provides a battery, preferably a lithium ion battery, such as a lithium ion solid state battery, comprising an electrode according to the fifth aspect of the present application. DETAILED DESCRIPTION

[0020] The electrically conductive agent composition according to the first aspect of the present application comprises carbon black (CB) and at least one material selected from the group consisting of carbon nanostructures (CNS), fragments of carbon nanostructures, and broken multi-walled carbon nanotubes.

[0021] As used herein, the term "carbon nanostructure" or "CNS" refers to a plurality of carbon nanotubes (CNTs), in many cases multi-walled carbon nanotubes (MWCNTs), that can be crosslinked and branched to one another, or a plurality of carbon nanotubes (CNTs), in many cases multi-walled carbon nanotubes (MWCNTs), that can exist as polymeric structures by being intertwined, branched, entangled, and / or sharing common walls with one another. Thus, a CNS can be considered to have CNTs, e.g., MWCNTs, as its polymeric structural building block monomer units. Typically, a CNS is grown on a substrate (e.g., a fibrous material) under CNS growth conditions. In such cases, at least a portion of the CNTs in the CNS can be oriented substantially parallel to one another, much like the parallel CNT orientation seen in conventional carbon nanotube bushes.

[0022] A highly entangled CNS is macroscopically visible in size and can be considered to have CNTs as its polymeric structural building block monomer units. For many of the CNTs in a CNS structure, at least a portion of the CNT sidewalls are shared with additional CNTs. While it is generally understood that each carbon nanotube in a CNS need not necessarily be branched, crosslinked, or share a common wall with other CNTs, at least a portion of the CNTs in a carbon nanostructure can be intertwined with one another and / or with branched, crosslinked, or co-walled carbon nanotubes in the remaining portion of the carbon nanostructure.

[0023] As known in the art, carbon nanotubes (CNTs) are carbonaceous materials comprising at least one sheet of sp2 hybridized carbon atoms that are bonded to one another to form a honeycomb lattice that forms a cylindrical or tubular structure. Carbon nanotubes can be single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs). SWCNTs can be thought of as an allotrope of sp2 hybridized carbon similar to fullerenes. The structure is a cylindrical tube comprising hexagonal carbon rings. On the other hand, similar MWCNTs have several tubes in the form of concentric cylinders. The number of these concentric walls can vary, for example, from 2 to 25 or more. Typically, MWNTs can be 10 nm or more in diameter, in contrast to typical SWNTs of 0.7-2.0 nm.

[0024] Because the CNS is a polymeric, highly branched and crosslinked network of CNTs, some of the chemical properties observed for individualized CNTs can also be realized on the CNS. In addition, some of the attractive properties often associated with the use of CNTs are also displayed in materials incorporating CNSs. These include, for example, electrical conductivity; attractive physical properties including, for example, good tensile strength, thermal stability (sometimes rivaling that of diamond crystals or in-plane graphite sheets) and / or chemical stability when integrated into composites, for example, thermoplastic or thermoset compounds (compounds).

[0025] However, as used herein, the term "CNS" is not synonymous with individualized, untangled structures such as "monomeric" fullerenes (the term "fullerenes" broadly refers to hollow spheres, tubes such as carbon nanotubes, and other shaped forms of carbon allotropes). Rather, many embodiments of the present invention highlight observed or expected differences and advantages in using CNSs as opposed to using CNT building blocks thereof. Without wishing to be bound to a particular explanation, it is believed that the combination of branching, crosslinking, and co-walling between carbon nanotubes in a CNS minimizes or minimizes van der Waals forces that are often problematic when using individual carbon nanotubes in a similar manner.

[0026] Additionally or alternatively, for performance attributes, CNTs that are part of or derived from a CNS can be characterized by a number of features, at least some of which can be relied upon to distinguish them from nanomaterials such as ordinary CNTs (i.e., CNTs that are not derived from a CNS and can be provided as individualized, pristine, or fresh CNTs).

[0027] In CNSs used in accordance with the present application, the CNTs are MWCNTs having, for example, at least 2 coaxial carbon nanotubes. The number of walls present can be in the range of about 2-30, for example: 4-30; 6-30; 8-30; 10-30; 12-30; 14-30; 16-30; 18-30; 20-30; 22-30; 24-30; 26-30; 28-30; or 2-28; 4-28; 6-28; 8-28; 10-28; 12-28; 14-28; 16-28; 18-28; 20-28; 22-28; 24-28; 26-28; or 2-26; 4-26; 6-26; 8-26; 10-26; 12-26; 14-26; 16-26; 18-26; 20-26; 22-26; 24-26; or 2-24; 4-24; 6-24; 8-24; 10-24; 12-24; 14-24; 16-24; 18-24; 20-24; 22-24; or 2-22; 4-22; 6-22; 8-22; 10-22; 12-22; 14-22; 16-22; 18-22; 20-22; or 2-20; 4-20; 6-20; 8-20; 10-20; 12-20; 14-20; 16-20; 18-20; or 2-18; 4-18; 6-18; 8-18; 10-18; 12-18; 14-18; 16-18; or 2-16; 4-16; 6-16; 8-16; 10-16; 12-16; 14-16; or 2-14; 4-14; 6-14; 8-14; 10-14; 12-14; or 2-12; 4-12; 6-12; 8-12; 10-12; or 2-10; 4-10; 6-10; 8-10; or 2-8; 4-8; 6-8; or 2-6; 4-6; or 2-4, as determined, for example, by transmission electron microscopy (TEM) at a magnification sufficient to analyze the number of walls in the particular case.

[0028] In preferred embodiments of the application, at least one of the CNSs, fragments of CNSs, or CNTs derived from the broken CNSs of the application has a typical diameter of 100 nanometers (nm) or less, for example in the range of about 5 to about 100 nm, for example in the range of about 10 to about 75, about 10 to about 50, about 10 to about 30, about 10 to about 20 nm.

[0029] In preferred embodiments of the application, at least one of the CNSs, fragments of CNSs, or broken CNTs derived from the CNSs of the application has a length equal to or greater than 2 microns, as determined by SEM. For example, at least one of the CNSs, fragments of CNSs, or broken CNTs derived from the CNSs has a length in the range of 2-2.25 microns; 2-2.5 microns; 2-2.75 microns; 2-3.0 microns; 2-3.5 microns; 2-4.0 microns; or 2.25-2.5 microns; 2.25-2.75 microns; 2.25-3 microns; 2.25-3.5 microns; 2.25-4 microns; or 2.5-2.75 microns; 2.5-3 microns; 2.5-3.5 microns; 2.5-4 microns; or 3-3.5 microns; 3-4 microns; 3.5-4 microns or higher. In some embodiments, more than one, e.g., a fraction, e.g., at least about 0.1%, at least about 1%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40, at least about 45%, at least about 50%, or even more than half of the SWCNTs, as determined by SEM, can have a length greater than 2 microns, e.g., in the ranges described above.

[0030] The morphology of the CNSs, fragments of CNSs, or broken CNTs derived from the CNSs of the application is characterized by a high aspect ratio, where the length is typically greater than 100 times the diameter, and in some cases even higher. For example, the length to diameter aspect ratio can be in the range of about 200 to about 1000, e.g., 200-300; 200-400; 200-500; 200-600; 200-700; 200-800; 200-900; or 300-400; 300-500; 300-600; 300-700; 300-800; 300-900; 300-1000; or 400-500; 400-600; 400-700; 400-800; 400-900; 400-1000; or 500-600; 500-700; 500-800; 500-900; 500-1000; or 600-700; 600-800; 600-900; 600-1000; 700-800; 700-900; 700-1000; or 800-900; 800-1000; or 900-1000.

[0031] It has been found that at least one of the CNS, a fragment of the CNS, or a broken CNT derived from the CNS is characterized by a certain "branching density." As used herein, the term "branching" refers to a feature in which a single carbon nanotube bifurcates into multiple (two or more), connected multi-walled carbon nanotubes. One embodiment has a branching density according to which there are at least two branches along a 2 micrometer length of the carbon nanostructure, as determined by SEM. Three or more branches can also occur.

[0032] Further features (detected using, for example, TEM or SEM) can be used to characterize the type of branching found in CNS relative to structures that are not derived from CNS, such as Y-shaped CNTs. For example, while Y-shaped CNTs have a catalyst particle at or near the branching region (point), no such catalyst particle is present at or near the branching region that occurs in CNS, fragments of CNS, or broken CNTs.

[0033] In addition, or alternatively, the number of walls observed at the branching region (point) in CNS, fragments of CNS, or broken CNTs differs from one side of the branching (e.g., before the branching point) to the other side of the region (e.g., after the branching point or beyond the branching point). Such a change in the number of walls, also referred to herein as "asymmetry" in the number of walls, is not observed for ordinary Y-shaped CNTs, in which the same number of walls is observed both in the region before the branching point and in the region beyond the branching point.

[0034] In some embodiments, CNS exist as part of a tangled and / or interconnected network of CNS. Such an interconnected network can contain bridges between CNS.

[0035] Suitable techniques for making CNS are described, for example, in U.S. Patent Application Publication No. 2014 / 0093728 Al, published April 3, 2014; U.S. Patent Nos. 8,784,937 B2; 9,005,755 B2; 9,107,292 B2; and 9,447,259 B2. The entire contents of these documents are incorporated herein by reference.

[0036] As described in these documents, CNS can be grown on a suitable substrate, such as a catalyst-treated fibrous material. The product can be a CNS material containing fibers. In some cases, the CNS are separated from the substrate to form a flake.

[0037] As seen in US 2014 / 0093728 Al, carbon nanostructures obtained as flake material (i.e., discrete particles having limited dimensions) exist as three-dimensional microstructures due to the entanglement and cross-linking of their highly oriented carbon nanotubes. This oriented morphology reflects the formation of carbon nanotubes on the growth substrate under fast carbon nanotube growth conditions (e.g., several microns per second, such as about 2 microns per second to about 10 microns per second), resulting in a substantially perpendicular carbon nanotube growth from the growth substrate. Without being bound by any theory or mechanism, it is believed that the fast carbon nanotube growth rate on the growth substrate can at least partially contribute to the complex structural morphology of the carbon nanostructures. Moreover, by adjusting the carbon nanostructure growth conditions, including, for example, by varying the concentration of transition metal nanoparticle catalyst particles disposed on the growth substrate to initiate carbon nanotube growth, the packing density of the CNS can be adjusted to some extent.

[0038] The flakes can be further processed, such as by cutting or fuzzing (which can involve operations of mechanical ball milling, milling, blending, etc.), chemical processes, or any combination thereof.

[0039] In some embodiments, the CNS employed is a "coated," also referred to herein as "sized," or "encapsulated" CNS. In a typical sizing process, a coating is applied to the CNTs that form the CNS. The sizing process can form a partial or complete coating that non-covalently binds to the CNTs and in some cases can act as a binder. Additionally, or alternatively, a sizing agent can be applied to the CNS that has already been formed in a post-coating process. In cases where the sizing agent has adhesive properties, the CNS can be formed into larger structures, such as granules or pellets. In other embodiments, the granules or pellets are formed independently of the function of the sizing.

[0040] The amount of coating can vary. For example, the coating can be in the range of about 0.1 wt% to about 10 wt% (e.g., in the following ranges by weight: about 0.1% to about 0.5%; about 0.5% to about 1%; about 1% to about 1.5%; about 1.5% to about 2%; about 2% to about 2.5%; about 2.5% to about 3%; about 3% to about 3.5%; about 3.5% to about 4%; about 4% to about 4.5%; about 4.5% to about 5%; about 5% to about 5.5%; about 5.5% to about 6%; about 6% to about 6.5%; about 6.5% to about 7%; about 7% to about 7.5%; about 7.5% to about 8%; about 8% to about 8.5%; about 8.5% to about 9%; about 9% to about 9.5%; or about 9.5% to about 10%) relative to the total weight of the coated CNS material.

[0041] In many cases, the amount of the coating layer (or sizing agent) is controlled to minimize or reduce undesirable effects on the properties of the CNS material itself. Low coating levels are more likely, for example, to preserve the electrical properties that result from the introduction of CNS or CNS-derived materials (e.g., CNS fragments of broken CNTs) into the positive electrode composition.

[0042] A variety of types of coating layers can be selected. In many cases, sizing solutions commonly used in coating carbon or glass fibers can also be used to coat the CNS. Specific examples of coating materials include, but are not limited to, fluorinated polymers such as poly(vinyl difluoroethylene) (PVDF), poly(vinyl difluoroethylene-co-hexafluoro propylene) (PVDF-HFP), poly(tetrafluoroethylene) (PTFE), polyimides, and water-soluble binders such as poly(ethylene oxide), polyvinyl alcohol (PVA), cellulose, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone (PVP), and copolymers and mixtures thereof. In many implementations, the CNS used is treated with polyurethane (PU), thermoplastic polyurethane (TPU), or with polyethylene glycol (PEG).

[0043] In some cases, polymers such as epoxy resins, polyesters, vinyl esters, polyetherimides, polyetherketone ketone, polyphthalamides, polyetherketone, polyether ether ketone, polyimides, phenol-formaldehyde, bismaleimides, acrylonitrile-butadiene styrene (ABS), polycarbonates, polyethyleneimines, polyurethanes, polyvinylchlorides, polystyrenes, polyolefins, polypropylenes, polyethylenes, polytetrafluoroethylenes, elastomers such as polyisoprene, polybutadiene, butyl rubber, nitrile rubber, ethylene-vinyl acetate polymers, silicone polymers, and fluorosilicone polymers, combinations thereof, or other polymers or polymer blends can also be used. To enhance electrical conductivity, conductive polymers such as polyanilines, polypyrroles, and polythiophenes can also be used.

[0044] Some implementations employ a coating material that can assist in stabilizing the CNS dispersion in solvent. In one example, the coating layer is selected to promote and / or stabilize the dispersion of the CNS in a medium, which can be, for example, N-methyl pyrrolidone (NMP), acetone, a suitable alcohol, water, or any combination thereof.

[0045] Many of the implementations described herein use CNS materials having a CNT purity of 97% or greater. Typically, the anionic, cationic, or metallic impurities are very low, for example, in the range of a few parts per million (ppm). Often, the CNS used herein does not require further additives to counteract van der Waals forces.

[0046] The CNS can be provided in the form of loose particulate material (as, for example, CNS flakes, granules, pellets, etc.) or in a composition further including a liquid medium, such as a dispersion, slurry, paste, or in other forms. In many implementations, the CNS employed is free of any growth substrate.

[0047] In some embodiments, the CNS is provided in the form of flake material after removal from the growth substrate on which the carbon nanostructures were initially formed. As used herein, the term "flake material" refers to discrete particles having limited dimensions.

[0048] The CNTs within the CNS can vary in length, for example, between about 10 nanometers and about 750 micrometers. In illustrative implementations, the CNTs are about 10 nanometers to about 100 nanometers, about 100 nanometers to about 500 nanometers, about 500 nanometers to about 1 micrometer, about 1 micrometer to about 10 micrometers, about 10 micrometers to about 100 micrometers, about 100 micrometers to about 250 micrometers, about 250 to about 500 micrometers, or about 500 micrometers to about 750 micrometers.

[0049] The flake structure can include a reticulated network of carbon nanotubes in the form of carbon nanotube polymers (i.e., "carbon nanopolymer") having a molecular weight in the range of about 15,000 g / mol to about 150,000 g / mol, including all values therebetween and any portion thereof. In some cases, the upper limit of the molecular weight range can be even higher, including about 200,000 g / mol, about 500,000 g / mol, or about 1,000,000 g / mol. This higher molecular weight can be associated with long carbon nanostructures in terms of dimensions. The molecular weight can also be a function of the dominant carbon nanotube diameter and the number of carbon nanotube walls present within the carbon nanostructure. The crosslinking density of the carbon nanostructure can range from about 2 mol / cm 3 to about 80 mol / cm 3 Typically, the crosslinking density is a function of the carbon nanostructure growth density on the growth substrate surface, carbon nanostructure growth conditions, etc. It should be noted that typical CNS structures, which contain many many CNTs held in an open network arrangement, remove or reduce the influence of van der Waals forces. This structure can be more easily exfoliated, which makes the separation of them or the breaking of them into many additional steps unique and different from ordinary CNTs.

[0050] With a network morphology, the carbon nanostructures can have a relatively low bulk density. The carbon nanostructures produced can have a bulk density ranging from about 0.003 g / cm 3 to about 0.015 g / cm 3the initial bulk density. Further consolidation and / or coating to produce carbon nanostructure flake material or similar morphology can increase the bulk density to a range of about 0.1 g / cm 3 - about 0.15 g / cm 3 In some embodiments, optional further modification of the carbon nanostructures can be performed to further alter the bulk density and / or additional properties of the carbon nanostructures. In some embodiments, the bulk density of the carbon nanostructures can be further altered by forming a coating on the carbon nanotubes of the carbon nanostructures and / or infiltrating the interior of the carbon nanostructures with various materials. Coating the carbon nanotubes and / or infiltrating the interior of the carbon nanostructures can further tailor the properties of the carbon nanostructures for use in various applications. Additionally, forming a coating on the carbon nanotubes can desirably facilitate handling of the carbon nanostructures. Further compaction can increase the bulk density to an upper limit of about 1 g / cm 3 and chemical modification of the carbon nanostructures increases the bulk density to an upper limit of about 1.2 g / cm 3 .

[0051] In addition to the flakes described above, CNS materials can be provided as granules, pellets, or other forms of loose particulate material having a typical particle size in a range of about 1 mm to about 1 cm, for example, about 0.5 mm to about 1 mm, about 1 mm to about 2 mm, about 2 mm to about 3 mm, about 3 mm to about 4 mm, about 4 mm to about 5 mm, about 5 mm to about 6 mm, about 6 mm to about 7 mm, about 7 mm to about 8 mm, about 8 mm to about 9 mm, or about 9 mm to about 10 mm.

[0052] The bulk density of CNS materials that can be employed can be in a range of about 0.005 g / cm 3 - about 0.1 g / cm 3 , for example, about 0.01 g / cm3to about 0.05 g / cm3.

[0053] Examples of CNS materials that can be utilized commercially are those developed by Applied Nanostructured Solutions, LLC (ANS) (Massachusetts, United States).

[0054] The CNS used herein can be confirmed and / or characterized by a variety of techniques. For example, electron microscopy techniques, including, for example, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) can provide information about, for example, the frequency of specific numbers of walls present, branching, absence of catalyst particles, etc.

[0055] Raman spectroscopy can indicate bands associated with impurities. For example, the D-band (about 1350 cm"1) is associated with amorphous carbon; the G band (about 1580 cm"1) is associated with crystalline graphite or CNTs). The G' band (about 2700 cm"1) is expected to occur at about twice the frequency of the D band. In some cases, it can be possible to distinguish between CNS and CNT structures by thermogravimetric analysis (TGA).

[0056] According to the present application, at least one of CNS, fragments of CNS, and broken CNTs is used together with carbon black (CB).

[0057] According to the present application, the carbon black used has a Brunauer-Emmett-Teller (BET) surface area greater than 200 m 2 / g.

[0058] In a preferred embodiment of the present application, the carbon black has a Brunauer-Emmett-Teller (BET) surface area greater than 200 m 2 / g, 300 m 2 / g, 400 m 2 / g, 500 m 2 / g, 600 m 2 / g, 700 m 2 / g, 800 m 2 / g, 900 m 2 / g, 1000 m 2 / g, 1200 m 2 / g, 1400 m 2 / g, 1600 m 2 / g, 1800 m 2 / g. In a preferred embodiment, the CB has a BET in one of the following ranges: 300 m 2 / g to 2000 m 2 / g, preferably 400 m 2 / g to 1800 m 2 / g, preferably 500 m 2 / g to 1600 m 2 / g, preferably 600 m 2 / g to 1400 m 2 / g, preferably 700 m 2 / g to 1000 m 2 / g, most preferably 800 m 2 / g to 900 m 2 / g, or 800 m 2 / g to 1600 m 2 / g. All BET surface area values disclosed herein refer to "BET nitrogen surface area" and are calculated using a physical adsorption instrument from nitrogen adsorption at liquid nitrogen temperature.

[0059] In preferred embodiments of the present application, the carbon black has one or more of the following characteristics: (1) a surface energy no higher than 20 mJ / m 2 ; (2) a La crystallite size of as measured by Raman spectroscopy, and (3) a Lc crystallite size of

[0060] CB suitable for use in the present application can have a surface energy as measured by dynamic vapor sorption (DVS) or water diffusion pressure of no higher than 20 mJ / m 2 , no higher than 19 mJ / m 2 , no higher than 18 mJ / m 2 , no higher than 17 mJ / m 2 , no higher than 16 mJ / m 2 , no higher than 15 mJ / m 2 , e.g., up to 12 mJ / m 2 , 10 mJ / m 2 , 8 mJ / m 2 , 6 mJ / m 2 , 4 mJ / m 2 , 2 mJ / m 2 . The lower limit of the surface energy of CB used in the present application is not particularly limited, but can be, for example, 0.01 mJ / m 2 , 0.1 mJ / m 2 , 1 mJ / m 2 , 2 mJ / m 2 , 3 mJ / m 2 , 6 mJ / m 2 , 10 mJ / m 2 , 12 mJ / m 2 , 13 mJ / m 2 , or 14 mJ / m 2 . The surface energy of CB can have or include any range and subranges resulting from combinations of the upper and lower limits listed above, e.g., one of the following ranges: 0.01 mJ / m 2 to 20 mJ / m 2 , 0.01 mJ / m2 to 18 mJ / m 2 , 0.01 mJ / m 2 to 17 mJ / m 2 , 0.01 mJ / m 2 to 16 mJ / m 2 , 0.01 mJ / m 2 to less than 15 mJ / m 2 , 0.1 mJ / m 2 to less than 15 mJ / m 2 , 1 mJ / m 2 to less than 15 mJ / m 2 , 2 mJ / m 2 to less than 15 mJ / m 2 , 3 mJ / m 2 to less than 15 mJ / m 2 , 6 mJ / m 2 to less than 15 mJ / m 2 , 10 mJ / m 2 to less than 15 mJ / m 2 , 12 mJ / m 2 to less than 15 mJ / m 2 , 13 mJ / m 2 to less than 15 mJ / m 2 , 14 mJ / m 2 to less than 15 mJ / m 2 , 0.01 mJ / m 2 to 14 mJ / m 2 , 0.1 mJ / m 2 to 14 mJ / m 2 , 1 mJ / m 2 to 14 mJ / m 2 , 2 mJ / m 2 to 14 mJ / m 2 , 3 mJ / m 2 to 14 mJ / m 2 , 6 mJ / m 2 to 14 mJ / m 2 , 10 mJ / m 2 to 14 mJ / m 2 , 12 mJ / m 2 to 14 mJ / m 2 , 13 mJ / m 2 to 14 mJ / m 2 , 0.01 mJ / m 2 to 13 mJ / m 2 , 0.1 mJ / m 2 to 13 mJ / m 2 , 1 mJ / m 2to 13 mJ / m 2 , 2 mJ / m 2 to 13 mJ / m 2 , 3 mJ / m 2 to 13 mJ / m 2 , 6 mJ / m 2 to 13 mJ / m 2 , 10 mJ / m 2 to 13 mJ / m 2 , 12 mJ / m 2 to 13 mJ / m 2 , 0.01 mJ / m 2 to 12 mJ / m 2 , 0.1 mJ / m 2 to 12 mJ / m 2 , 1 mJ / m 2 to 12 mJ / m 2 , 2 mJ / m 2 to 12 mJ / m 2 , 3 mJ / m 2 to 12 mJ / m 2 , 6 mJ / m 2 to 12 mJ / m 2 , 10 mJ / m 2 to 12 mJ / m 2 , 0.01 mJ / m 2 to 10 mJ / m 2 , 0.1 mJ / m 2 to 10 mJ / m 2 , 1 mJ / m 2 to 10 mJ / m 2 , 2 mJ / m 2 to 10 mJ / m 2 , 3 mJ / m 2 to 10 mJ / m 2 , 6 mJ / m 2 to 10 mJ / m 2 , 0.01 mJ / m 2 to 6 mJ / m 2 , 0.1 mJ / m 2 to 6 mJ / m 2 , 1 mJ / m 2 to 6 mJ / m 2 , 2 mJ / m 2 to 6 mJ / m 2 , 3 mJ / m 2 to 6 mJ / m 2 , 0.01 mJ / m 2 to 3 mJ / m 2 , 0.1 mJ / m 2 to 3 mJ / m2 1 mJ / m 2 2 mJ / m 2 3 mJ / m 2 4 mJ / m 2 5 mJ / m 2 6 mJ / m 2 7 mJ / m 2 8 mJ / m 2 9 mJ / m 2 10 mJ / m 2 11 mJ / m 2 12 mJ / m 2 13 mJ / m 2 14 mJ / m 2 15 mJ / m 2 16 mJ / m 2 17 mJ / m 2 18 mJ / m 2 19 mJ / m 2 20 mJ / m 2 .

[0061] CBs suitable for use in the present application can also have a La crystallite size, as measured by Raman spectroscopy, of La is defined as 43.5 x (G band area / D band area), and Raman measurements of La are based on Gruber et al., "Raman studies of heat-treated carbon blacks," Carbon, Vol. 32(7), pp. 1377-1382, 1994, which is incorporated herein by reference. The Raman spectrum of carbon includes two main "resonance" bands at about 1340 cm -1 and 1580 cm -1 , which are denoted as the "D" and "G" bands, respectively. It is generally accepted that the D band is attributed to disordered sp 2 2 carbon, and the G band is attributed to graphitic or "ordered" sp2carbon. The lower limit of the La crystallite size can be, for example, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, or The upper limit of the La crystallite size can be, for example, 48, 46, 44, 42, 40, 38, 36, 34, 32, 30, 28, 26, 24, 22, 20, 18, 16, 14, or The La crystallite size can have or include any range, and subranges thereof, resulting from combinations of the above recited upper and lower limits, for example, one of the following ranges: 15 to 20 to 30 to 35 to 36 to 36 to 36 to 36 to 36 to 37.5 to 37.5 to 37.5 to 37.5 to 37.5 to 40 to 40 to 40 to 40 to 42.5 to 45 to 12 to 14 to 16 to or 18 to

[0062] Further, CBs suitable for use in the present application can have an Lc crystallite size, as measured by X-ray diffraction (XRD) pattern, of Lc crystallite size, as measured by X-ray diffraction (XRD) pattern, of c The crystallite size was determined by X-ray diffraction using an X-ray diffractometer (PANalytical X’Pert Pro, PANalytical B.V.) with a copper tube, a tube voltage of 45 kV, and a tube current of 40 mA. A sample of carbon black particles was packed in a sample holder (accessory of the diffractometer), and the measurement was performed over an angular (2 theta) range of 10°-80° at a rate of 0.14° / min. The peak positions and full width at half maximum values were calculated by the software of the diffractometer. For the measurement angle calibration, lanthanum hexaboride (LaB6) was used as an X-ray standard. From the obtained measurement results, the Lc crystallite size was determined using the Scherrer equation c crystallite size: where K is a shape factor constant (0.9); l is the wavelength of the characteristic X-ray spectrum line of Cu K α1 of 1.5418 A beta is the peak width at half maximum in radian; and theta is determined by taking half of the measured angular peak position (2 theta). Suitable CBs have an Lc crystallite size of at least for example, 10 to Lc crystallite size. The lower limit of the Lc crystallite size can be, for example, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, or The upper limit of the Lc crystallite size can be, for example, 48, 46, 44, 42, 40, 38, 36, 34, 32, 30, 28, 26, 24, 22, 20, 18, 16, 14, or The Lc crystallite size can have or include any range, and subranges thereof, resulting from combinations of the above recited upper and lower limits, for example, one of the following ranges: 15 to 20 to 27.5 to 27.5 to 27.5 to 27.5 to 27.5 to 27.5 to 27.5 to 27.5 to 27.5 to 30 to 30 to 30 to 30 to 30 to 30 to 30 to 30 to 32.5 to 32.5 to 32.5 to 32.5 to 32.5 to 32.5 to 32.5 to 35 to 35 to 35 to 35 to 35 to 35 to 37.5 to 37.5 to 37.5 to 37.5 to 37.5 to 40 to 40 to 40 to 40 to 42.5 to 42.5 to 42.5 to 45 to 47.5 to 10 to 10 to 10 to or 10 to

[0063] In preferred embodiments of the application, the carbon black has the BET specific surface area recited above, and also one, two, or three of (1) the surface energy recited above, (2) the La recited above, and (3) the Lcrecited above.

[0064] In a preferred embodiment according to the present application, the material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures, and broken multiwall carbon nanotubes is present in the conductive agent composition of the present application in an amount of at least 1 wt%, preferably 1 to 65 wt%, more preferably 1 to 60 wt%, based on the total weight of the conductive agent composition. When the amount of the material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures, and broken multiwall carbon nanotubes is added within the range, the electrode manufactured with the conductive agent composition according to the present application has significantly improved conductivity, and at the same time, the battery using the electrode has excellent low temperature performance. The lower limit of the amount of the material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures, and broken multiwall carbon nanotubes can be, for example, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, or 58 wt%. The upper limit of the amount of the material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures, and broken multiwall carbon nanotubes can be, for example, 58, 56, 54, 52, 50, 48, 46, 44, 42, 40, 38, 36, 34, 32, 30, 28, 26, 24, 22, 20, 18, 16, 14, 12, 10, 8, 6, 4, or 2 wt%. The amount of the material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures, and broken multiwall carbon nanotubes included in the conductive agent composition of the present application can have or include any range and subranges resulting from combinations of the above recited upper and lower limits, for example, within one of the following ranges: 1.1 to 65 wt%, 1.5 to 65 wt%, 2 to 65 wt%, 5 to 65 wt%, 10 to 65 wt%, 1.1 to 60 wt%, 1.5 to 60 wt%, 2 to 60 wt%, 5 to 60 wt%, 10 to 60 wt%, 15 to 60 wt%, 20 to 60 wt%, 25 to 60 wt%, 30 to 60 wt%, 35 to 60 wt%, 40 to 60 wt%, 45 to 60 wt%, 50 to 60 wt%, 55 to 60 wt%, 1.1 to 58 wt%, 1.5 to 58 wt%, 2 to 58 wt%, 5 to 58 wt%, 10 to 58 wt%, 15 to 58 wt%, 20 to 58 wt%, 25 to 58 wt%, 30 to 58 wt%, 35 to 58 wt%, 40 to 58 wt%, 45 to 58 wt%, 50 to 58 wt%, 55 to 58 wt%, 1.1 to 56 wt%, 1.5 to 56 wt%, 2 to 56 wt%, 5 to 56 wt%, 10 to 56 wt%, 15 to 56 wt%, 20 to 56 wt%, 25 to 56 wt%, 30 to 56 wt%, 35 to 56 wt%, 40 to 56 wt%, 45 to 56 wt%, 50 to 56 wt%, or 55 to 56 wt%.

[0065] In preferred embodiments according to the present application, the carbon black employed in the present application is present in the conductive agent composition of the present application in an amount of at least 35 weight percent, preferably at least 40 weight percent, more preferably 40 to 99 weight percent, based on the total weight of the conductive agent composition. The lower limit of the amount of carbon black can be, for example, 36, 38, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, or 98 weight percent. The upper limit of the amount of carbon black can be, for example, 98, 96, 94, 92, 90, 88, 86, 84, 82, 80, 78, 76, 74, 72, 70, 68, 66, 64, 62, 60, 58, 56, 54, 52, 50, 48, 46, 44, 42, 38, or 36 weight percent. The amount of carbon black of the present application can have or include any range resulting from combinations of the above-enumerated upper and lower limits and subranges thereof, for example, in one of the following ranges: 35 to 98.9 weight percent, 35 to 98.5 weight percent, 35 to 98 weight percent, 35 to 95 weight percent, 35 to 90 weight percent, 40 to 98.9 weight percent, 40 to 98.5 weight percent, 40 to 98 weight percent, 40 to 95 weight percent, 40 to 90 weight percent, 40 to 85 weight percent, 40 to 80 weight percent, 40 to 75 weight percent, 40 to 70 weight percent, 40 to 65 weight percent, 40 to 60 weight percent, 40 to 55 weight percent, 40 to 50 weight percent, 40 to 45 weight percent, 42 to 98.9 weight percent, 42 to 98.5 weight percent, 42 to 98 weight percent, 42 to 95 weight percent, 42 to 90 weight percent, 42 to 85 weight percent, 42 to 80 weight percent, 42 to 75 weight percent, 42 to 70 weight percent, 42 to 65 weight percent, 42 to 60 weight percent, 42 to 55 weight percent, 42 to 50 weight percent, 42 to 45 weight percent, 44 to 98.9 weight percent, 44 to 98.5 weight percent, 44 to 98 weight percent, 44 to 95 weight percent, 44 to 90 weight percent, 44 to 85 weight percent, 44 to 80 weight percent, 44 to 75 weight percent, 44 to 70 weight percent, 44 to 65 weight percent, 44 to 60 weight percent, 44 to 55 weight percent, 44 to 50 weight percent, or 44 to 45 weight percent. When the conductive agent composition of the present application consists of the carbon black and the at least one material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures, and broken multiwall carbon nanotubes, the weight percentages of these components add up to 100 weight percent.

[0066] In addition, the conductive agent composition of the present application can further include carbon nanotubes in an isolated pristine form. The carbon nanotubes in the isolated pristine form include at least one selected from the group consisting of single-wall carbon nanotubes, few-wall carbon nanotubes, and multi-wall carbon nanotubes, preferably, the carbon nanotubes have a diameter of 1500 nm or less.2 / g or lower. The lower limit of the BET specific surface area of the carbon nanotubes is not particularly limited, but can be, for example, 50 m 2 / g, 100 m 2 / g, 150 m 2 / g, 200 m 2 / g, 250 m 2 / g, 300 m 2 / g, 350 m 2 / g, 400 m 2 / g, 450 m 2 / g, 500 m 2 / g, 550 m 2 / g, 600 m 2 / g, 650 m 2 / g, 700 m 2 / g, 750 m 2 / g, 800 m 2 / g, 850 m 2 / g, 900 m 2 / g, 950 m 2 / g, 1000 m 2 / g, 1050 m 2 / g, 1100 m 2 / g, 1150 m 2 / g, 1200 m 2 / g, 1250 m 2 / g, 1300 m 2 / g, 1350 m 2 / g, 1400 m 2 / g, or 1450 m 2 / g, the BET specific surface area of the carbon nanotubes can have or include any range and subranges resulting from combinations of the above recited upper and lower limits, for example, one of the following ranges: 50 m 2 / g to 1500 m 2 / g, 50 m 2 / g to 1400 m 2 / g, 50 m 2 / g to 1200 m 2 / g, 50 m 2 / g to 1000 m 2 / g, 50 m 2 / g to 800 m 2 / g, 50 m 2 / g to 600 m 2 / g, 50 m 2 / g to 400 m 2 / g, 50 m 2 / g to 200 m2 / g, 100 m 2 / g to 1500 m 2 / g, 100 m 2 / g to 1400 m 2 / g, 100 m 2 / g to 1200 m 2 / g, 100 m 2 / g to 1000 m 2 / g, 100 m 2 / g to 800 m 2 / g, 100 m 2 / g to 600 m 2 / g, 100 m 2 / g to 400 m 2 / g, 100 m 2 / g to 300 m 2 / g, 100 m 2 / g to 200 m 2 / g, 150 m 2 / g to 1500 m 2 / g, 150 m 2 / g to 1400 m 2 / g, 150 m 2 / g to 1200 m 2 / g, 150 m 2 / g to 1000 m 2 / g, 150 m 2 / g to 800 m 2 / g, 150 m 2 / g to 600 m 2 / g, 150 m 2 / g to 400 m 2 / g, 150 m 2 / g to 300 m 2 / g, 150 m 2 / g to 200 m 2 / g, 200 m 2 / g to 1500 m 2 / g, 200 m 2 / g to 1400 m 2 / g, 200 m 2 / g to 1200 m 2 / g, 200 m 2 / g to 1000 m 2 / g, 200 m 2 / g to 800 m 2 / g, 200 m 2 / g to 600 m 2 / g, 200 m 2 / g to 400 m 2 / g, 200 m 2 / g to 300 m 2 / g, 250 m 2 / g to 1500 m 2 / g, 250 m 2 / g to 1400 m 2 / g, 250 m 2 / g to 1200 m 2 / g, 250 m 2 / g to 1000 m 2 / g, 250 m 2 / g to 800 m 2 / g, 250 m 2 / g to 600 m 2 / g, 250 m 2 / g to 400 m 2 / g, 300 m 2 / g to 1500 m 2 / g, 300 m 2 / g to 1400 m 2 / g, 300 m 2 / g to 1200 m 2 / g, 300 m 2 / g to 1000 m 2 / g, 300 m 2 / g to 800 m 2 / g, 300 m 2 / g to 600 m 2 / g or 300 m 2 / g to 400 m 2 / g.

[0067] The individualized pristine form of carbon nanotubes, if present, can be added to the conductive agent composition of the present application in amounts common in the art, preferably, for example, are present in the conductive agent composition of the present application in amounts ranging from 5 to 79 weight percent, 5 to 75 weight percent, 5 to 70 weight percent, 5 to 65 weight percent, 5 to 60 weight percent, 5 to 55 weight percent, 5 to 50 weight percent, 5 to 45 weight percent, 5 to 40 weight percent, 5 to 35 weight percent, 10 to 75 weight percent, 10 to 70 weight percent, 10 to 65 weight percent, 10 to 60 weight percent, 10 to 55 weight percent, 10 to 50 weight percent, 10 to 45 weight percent, 10 to 40 weight percent, or 10 to 35 weight percent, based on the total weight of the conductive agent composition. When the conductive agent composition of the present application consists of the individualized pristine form of carbon nanotubes, the carbon black, and the at least one material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures, and broken multiwall carbon nanotubes, the weight percentages of these components add up to 100 weight percent.

[0068] In a second aspect, the present application provides a conductive agent dispersion comprising a conductive agent composition according to the present application and a solvent.

[0069] Any suitable solvent known in the art can be used in the present application, as long as a stable dispersion of the conductive agent composition can be formed. In a preferred embodiment, suitable solvents can be selected from the group consisting of N-methyl pyrrolidone, water, methanol, ethanol, n-propanol, isopropanol, acetone, butanol, butanediol, pentane, n-hexane, cyclohexane, trichloroethane, carbon tetrachloride, ethyl acetate, methyl ethyl ketone, dimethylformamide, dimethylacetamide, benzene, xylene, dipropylene glycol methyl ether, tripropylene glycol methyl ether, dimethylsulfoxide, dihydrolevogluside, and combinations thereof.

[0070] In one embodiment, the conductive agent dispersion further comprises a dispersant.

[0071] The dispersant generally includes a material that is capable of facilitating the dispersion of at least one of a CNS-based material, i.e., carbon nanostructures, fragments of carbon nanostructures, and broken multi-walled carbon nanotubes, in a solvent (e.g., via steric and / or electrostatic charge mechanisms) while maintaining the viscosity of the composition low enough to enable practical processing of the composition, e.g., for manufacturing electrodes for batteries. In various embodiments, the composition can be referred to as a slurry, or paste, that can be readily applied or coated to a conductive substrate to form an electrode, as opposed to a mud that is too thick or too viscous to be effectively applied during manufacturing. In addition to its ability to disperse the CNS-based material, the dispersant is preferably thermally stable, electrochemically inert, and / or minimally impedes the electrical conductivity of the CNS-based material. A thermally stable or non-volatile dispersant allows the solvent to be removed and recycled during electrode manufacturing without removing and / or decomposing the dispersant. "Electrochemically inert" means that the dispersant is stable during the normal use of the battery (e.g., does not decompose or oxidize at or below the operating voltage of the battery) as such decomposition can negatively affect the performance of the battery. Furthermore, since the dispersant coats at least a portion of the CNS flakes, granules, pellets, etc. to disperse the particles, the dispersant will impede or reduce the electrically conductive contact surface available to the particles. The dispersant is preferably selected to minimally impede the electrical conductivity of the CNS particles.

[0072] Examples of suitable dispersants include polyvinylpyrrolidone, polyacrylamide, polycarboxylic acid, polyacrylic acid, polycarboxylate, polyacrylate, polyvinyl alcohol, montan wax, polyvinyl butyral, nitrile rubber, carboxymethyl cellulose, hydroxyethyl cellulose, polyethylene glycol, polyvinyl acetate, polystyrene sulfonate, polymethacrylate, polyvinyl imine, polyvinyl amine, polypropylene amine, polyacrylonitrile, poly(2-vinylpyridine), block copolyether, cellulose acetate, polyamide, polyimide, hydrogenated nitrile rubber, styrene-maleic anhydride copolymer, polyether sulfone, hydroxymethyl cellulose, chitosan, (hydroxy)ethyl cellulose, methyl cellulose, polyurethane, polyvinylidene fluoride, cellulose ether, silane coupling agent, polyoxyethylene ether, sodium lignosulfonate, derivatives of the above polymers, combinations thereof, and other dispersants known in the art. In preferred embodiments, the dispersant is selected from polyvinylpyrrolidone, polyacrylamide, polyacrylic acid, polyacrylate, montan wax, carboxymethyl cellulose, hydroxyethyl cellulose, polyethylene glycol, polyvinyl acetate, polyvinyl amine, polypropylene amine, polyacrylonitrile, poly(2-vinylpyridine), hydrogenated nitrile rubber, and styrene-maleic anhydride copolymer. In particularly preferred embodiments, hydrogenated nitrile rubber is used as the dispersant. In particular, hydrogenated nitrile rubber dispersants can improve the electrochemical stability of the battery to improve the overall electrochemical performance of the battery. The conductive agent dispersion can include one dispersant of one composition or multiple dispersants of different compositions.

[0073] In an embodiment, the electrically conductive agent dispersion further comprises a wetting agent. The wetting agent has a carbon atom number of 2 to 16, a boiling point of not more than 200°C at a standard atmospheric pressure, and a surface tension of not more than 50 mN / m at 25°C. The wetting agent is preferably selected from the group consisting of alcohol compounds, amine compounds, alcohol amine compounds, ether compounds, ester compounds, nitrile compounds, alkane compounds, siloxane compounds. The molecular structure of the wetting agent includes at least one of the following functional groups: hydroxyl group, primary amino group, secondary amino group, tertiary amino group, nitrile group, carbonyl group, ester group, acid anhydride group, ether bond, amide bond, urethane bond, siloxane bond.

[0074] In another embodiment, the electrically conductive agent dispersion according to the present application can comprise one or more additives, typically non-conductive additives, such as maleic anhydride polymers, in addition to the electrically conductive agent composition according to the present application, the solvent and the dispersant.

[0075] The electrically conductive agent composition according to the present application can be combined with a solvent, optionally in the presence of a dispersant, by suitable mixing techniques, using for example conventional mixing equipment.

[0076] Thus, in a third aspect, a method of preparing an electrically conductive agent dispersion according to the present application, comprising combining an electrically conductive agent composition according to the present application, a solvent, and optionally a dispersant, to form the dispersion.

[0077] In an embodiment, the electrically conductive agent dispersion is prepared by mixing and dispersing the electrically conductive agent composition, the dispersant and the solvent through a dispersing apparatus. Here, the dispersion time is not particularly limited. The dispersing apparatus can be, for example, a sand mill or a homogenizer.

[0078] In one embodiment, the constituent ingredients are blended to form a dispersion. The dispersion is, for example, characterized by a concentration of CNS-based material in the solvent of 0.1-10 wt.%, for example 0.25-5 wt.% or greater. In illustrative examples, the concentration in wt.% is in the range of 0.1-0.5, 0.5-0.75, 0.75-1.0, 1.0-1.25, 1.25-1.50, 1.50-1.75, 1.75-2.0, 2.0-2.25, 2.25-2.5, 2.5-2.75, 2.75-3.0, 3.0-3.25, 3.25-3.5, 3.5-3.75, 3.75-4.0, 4.0-4.25, 4.25-4.5, 4.5-4.75, 4.75-5.0, 5.0-5.25, 5.25-5.5, 5.5-5.75, 5.75-6.0, 6.0-6.25, 6.25-6.5, 6.5-6.75, 6.75-7.0, 7.0-7.25, 7.25-7.5, 7.5-7.75, 7.75-8.0, 8.0-8.25, 8.25-8.5, 8.5-8.75, 8.75-9.0, 9.0-9.25, 9.25-9.5, 9.5-9.75, or 9.75-10. Other concentrations of CNS-based material in the solvent can be employed.

[0079] For example, the above-described conductive agent composition or conductive agent dispersion, in combination with other ingredients, can be used, for example, in the manufacture of electrodes for many energy storage devices, for example, batteries, preferably lithium ion batteries. As one example, the conductive agent composition or conductive agent dispersion is used in the manufacture of electrode (e.g., positive / negative) compositions for lithium ion batteries. For example, the conductive agent composition or conductive agent dispersion can be combined with an electroactive material for a particular type of positive / negative electrode.

[0080] Thus, in a fourth aspect, the present application relates to the use of a conductive agent composition according to the present application or a conductive agent dispersion according to the present application for the manufacture of an electrode.

[0081] Further, in a fifth aspect, the present application provides an electrode, preferably for a lithium ion battery, comprising a current collector and an electrode active material layer, wherein the electrode active material layer comprises a conductive agent composition according to the present application.

[0082] In some embodiments, the electrode composition contains one or more binders, which, for example, serve to enhance the mechanical properties of the formed electrode. Exemplary binder materials include, but are not limited to, fluorinated polymers such as poly(vinyl difluoro ethylene) (PVDF), poly(vinyl difluoro ethylene-co-hexafluoro propylene) (PVDF-HFP), poly(tetrafluoro ethylene) (PTFE), polyimides, and water-soluble binders such as poly(ethylene oxide), polyvinyl alcohol (PVA), cellulose, carboxymethyl cellulose (CMC), styrene-butadiene rubber (SBR), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinyl pyrrolidone (PVP), and copolymers and mixtures thereof. Other possible binders include polyethylene, polypropylene, ethylene-propylene-diene terpolymers (EPDM), sulfonated EPDM, and fluoroelastomers and copolymers and mixtures thereof. In illustrative examples, the negative active material is graphite and the binder is PVDF or CMC with SBR.

[0083] The binder can be present in the electrode composition in an amount of about 1 to about 20 wt.%, for example, about 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10, 10-11, 11-12, 12-13, 13-14, 15-16, 16-17, 17-18, 18-19, or 19-20 wt.%.

[0084] In some embodiments, the loading of the conductive agent composition relative to the dry electrode composition is no greater than about 5 wt.% and often no greater than about 2 wt.%, for example, less than 1.9, 1.8, 1.7, or 1.6 wt.%. In other embodiments, the loading of the conductive agent composition relative to the dry electrode composition is 1.5 wt.% or less, for example, at least 1.4, 1.3, 1.2, 1.2, 1.0, 0.95, 0.90, 0.85, 0.80, 0.75, 0.70, 0.65, 0.60, 0.55, 0.50, 0.45, 0.40, 0.35, 0.30, 0.25, 0.20, 0.15, or 0.10 wt.%. In many embodiments, the loading of the conductive agent composition relative to the dry electrode composition (e.g., as used in a graphite negative electrode for a lithium battery) is no greater than 0.5 wt.%, for example, in the range of about 0.5 wt.% to about 0.1 wt.%, for example, in the range of about 0.1 to about 0.2, about 02 to about 0.3, about 0.3 to about 0.4, or about 0.4 to about 0.5 wt.%. Other embodiments employ a loading in the range of about 2 to about 5 wt.%, for example, a loading of at least about 2.25, 2.5, 2.75, 3.0, 3.25, 3.5, 3.75, 4.0, 4.25, 4.5, or 4.75.

[0085] The electrode composition can be prepared by combining (e.g., by uniformly mixing) the above-described constituent components, which can be added in any order to obtain a mixture and, in particular, a uniform mixture. Suitable mixing techniques include mechanical agitation, shaking, stirring, and the like.

[0086] In one example, the electrode composition is made by uniformly dispersing (e.g., by uniformly mixing) the electrically conductive agent composition or dispersion with the positive / negative active component. In another example, the binder is uniformly dispersed with the electrically conductive agent composition or dispersion and with the electroactive component.

[0087] The resulting electrode composition can be in the form of a paste or slurry that combines the positive / negative active material, the electrically conductive agent composition, the dispersant(s) (if present), the non-conductive additive(s) (if present), the solvent, and the binder (if present). In other embodiments, the electrode composition is a solid formed by removing the solvent from the paste or slurry. Drying techniques that can be employed include air drying, heating (e.g., in a suitable oven), and the like.

[0088] The battery electrode can be formed by applying the electrode composition (e.g., in the form of a paste) to a conductive substrate (e.g., an aluminum or copper current collector) and thereafter removing the solvent. The paste can be applied by techniques such as doctor blading, reverse comma bar coating, or extrusion.

[0089] In some implementations, the paste has a high enough solid loading (i.e., a high solid concentration) to enable deposition onto a substrate while minimizing the formation of inherent defects (e.g., cracking) that can arise with lower viscosity pastes (e.g., with lower solid loadings). In addition, higher solid loadings reduce the amount of solvent needed and its removal.

[0090] The solvent is removed by heating the paste at ambient temperature or at low heat conditions, such as temperatures ranging from 20 °C to 100 °C. The deposited electrode / current collector can be cut to the desired dimensions, optionally followed by calendering.

[0091] The process leading to the formation of the electrode can preserve some of the integrity of the original CNS-based material used, which will remain intact. However, some process operations and / or conditions can alter at least some of the original CNS-based material used. As described above, one example involving such operations and / or conditions is the application of shear forces, as encountered, for example, when preparing an emulsion from a CNS-based starting material.

[0092] In some cases, the initial CNS-based material is broken into smaller CNS units or fragments. In addition to their reduced size, these fragments generally share the properties of the intact CNS and can be confirmed by electron microscopy and other techniques, as described above.

[0093] It is also possible that the initial nanostructured morphology of the CNS-based material is changed. For example, the applied shear can break crosslinks between CNTs within the CNS-based material to form CNTs that will typically be dispersed as individual CNTs in the electrode composition. It is found that for many of these CNTs, the structural features of branching and shared walls are retained even after the crosslinks are removed. CNTs that are derived (prepared) from a CNS and retain the structural features of CNT branching and shared walls are referred to herein as “fractured” CNTs. These species are able to impart improved interconnectivity (between CNT units), resulting in better conductivity at lower concentrations.

[0094] These fractured CNTs can be readily distinguished from ordinary carbon nanotubes by standard carbon nanotube analysis techniques, such as SEM. It is further noted that not every CNT encountered need be branched and share a common wall; rather, it is the plurality of fractured CNTs that collectively will have these features.

[0095] Examples of suitable positive active materials include, but are not limited to, LCO, LMO, NCM, NCA, LCP, LFP, LFSF, LTS, and others as known in the art or as developed in the future. In some embodiments, the CNS-containing compositions described above are used in conjunction with NCM or NCA positive electrode compositions. NCM (also referred to as “NMC”) and NCA are well known to those skilled in the battery art.

[0096] In more detail, NCM can be represented by the formula Li 1+x (Ni y Co 1-y-z Mn z ) 1-x O2, where x ranges from 0-1, y ranges from 0-1 (e.g., 0.3-0.8), and z ranges from 0-1 (e.g., 0.1-0.3). Examples of NCM include Li 1+x (Ni 0.33 Co 0.33 Mn 0.33 ) 1-x O2, Li 1+x (Ni 0.4 Co 0.3 Mn 0.3 ) 1-x O2, Li 1+x (Ni 0.4 Co0.2 Mn 0.4 ) 1-x O2, Li 1+x (Ni 0.4 Co 0.1 Mn 0.5 ) 1-x O2, Li 1+x (Ni 0.5 Co 0.1 Mn 0.4 ) 1-x O2, Li 1+x (Ni 0.5 Co 0.3 Mn 0.2 ) 1-x O2, Li 1+x (Ni 0.5 Co 0.2 Mn 0.3 ) 1-x O2, Li 1+x (Ni 0.6 Co 0.2 Mn 0.2 ) 1-x O2, and Li 1+x (Ni 0.8 Co 0.1 Mn 0.1 ) 1-x O2.

[0097] NCA can be represented by the formula Li 1+x (Ni y Co 1-y-z Al z ) 1-x O2, where x ranges from 0-1, y ranges from 0-1, and z ranges from 0-1. One example of NCA is Li 1+x (Ni 0.8 Co 0.15 Al 0.05 ) 1-x O2.

[0098] The concentration of NCM or NCA in the electrode composition can vary depending on the specific type of energy storage device. In some cases, NCM or NCA is present in the electrode composition in an amount of at least 90 wt%, for example greater than 95 wt%, relative to the total weight of the electrode composition, for example in an amount ranging from 90 wt% to 99 wt%, relative to the total weight of the electrode composition.

[0099] In addition to the positive active material, the positive electrode composition often includes a binder such as poly(vinyl difluoro ethylene) (PVDF). Other binders such as those described above can be employed to prepare the positive electrode composition.

[0100] In a preferred embodiment according to the present application, the positive electrode is prepared by mixing the conductive agent dispersion of the present application, the positive electrode active material, polyvinylidene fluoride (PVDF) as a binder in a solvent N-methyl pyrrolidone (NMP) in a certain weight ratio to prepare a positive electrode slurry, and then coating on an aluminum foil as a positive electrode current collector, after which the solvent is removed.

[0101] Examples of suitable negative electrode active materials include, but are not limited to, graphite, such as, for example, natural graphite, artificial graphite, or a blend of the two. Commercially available types of graphite that can be used include mesocarbon microbeads (MCMB), mesophase pitch-based carbon fibers (MCF), vapor grown carbon fibers (VGCF), large-scale artificial graphite (MAG), natural graphite, and others. In other embodiments, the active negative compound used comprises, consists essentially of, or consists of silicon. In one example, the negative electrode active material is a silicon-graphite composite, containing nanosilicon (Si) or SiO x Graphite in particulate form.

[0102] The principles described herein can also be used for other negative electrode active materials such as those known or currently explored, or those developed in the future. Examples include, but are not limited to: (a) intercalation / deintercalation materials (e.g., carbon-based materials, porous carbon, carbon nanotubes, graphene, Ti02, Li4Ti50 12 , etc.); (b) alloy / dealloy materials (e.g., Si, SiO x , doped Si, Ge, Sn, Al, Bi, Sn02, etc.); and (c) conversion materials (e.g., transition metal oxides (Mn x O y , NiO, Fe x O y , CuO, Cu20, M0O2, etc.) represented by the formula M x X y metal sulfides, metal phosphides, and metal nitrides represented by the formula M

[0103] Negative electrode active materials such as graphite, silicon, lithium titanate (Li4Ti50 12 , also often referred to as "LTO"), SiO xThe concentration of the negative active material component, such as silicon-graphite composite, etc., can vary depending on the specific type of energy storage device. In illustrative examples, the negative active material component is present in the electrode composition in an amount of at least 80 wt.%, such as at least 85, 90, or 95 wt.%, for example, in an amount ranging from 80 wt.% to 99 wt.% of the total weight of the electrode composition, such as in a range of about 80 wt.% to about 85 wt.%, about 85 wt.% to about 88 wt.%, about 88 wt.% to about 90 wt.%, about 90 wt.% to about 92 wt.%, about 92 wt.% to about 95 wt.%, about 95 wt.% to about 97 wt.%, or about 97 wt.% to about 99 wt.% of the total weight of the electrode composition.

[0104] In some embodiments, the negative electrode composition contains, in addition to the negative active material, a conductive additive such as CB, CNT, graphite, graphene, etc., a binder such as styrene butadiene rubber (SBR), and a thickener such as carboxymethyl cellulose (CMC).

[0105] In a preferred embodiment according to the present application, the negative electrode is prepared by mixing carbon black as a conductive agent, graphite as an active material, a styrene butadiene rubber binder, and a carboxymethyl cellulose (CMC) thickener in a certain weight ratio in water to prepare a negative electrode slurry, and then coating on a copper foil as a negative electrode current collector, after which the solvent is removed.

[0106] In addition to these two electrodes, the Li-ion battery also contains a suitable electrolyte. Examples include, for example, ethylene carbonate-dimethyl carbonate-ethyl methyl carbonate (EC-DMC-EMC), vinylene carbonate (VC), LiPF6; ethylene carbonate-diethyl carbonate (EC-DEC, LiPF6; or (EC-DMC), LiPF6. In addition, the electrolyte composition can contain special additives known to enhance the performance of SiO x or silicon-based negative electrodes, such as fluorinated carbonates, for example, fluoroethylene carbonate, and others. A separator of suitable glass fiber micro-filter (e.g., Whatman GF / A) or polypropylene / polyethylene film (e.g., Celgard 2300) is used to absorb the electrolyte and prevent electrical contact between the electrodes, while allowing diffusion of Li ions.

[0107] The formed electrode can be incorporated into a lithium ion battery according to methods known in the art, for example as described in "Lithium Ion Batteries Fundamentals and Applications", Yuping Wu, CRC press, (2015). In some embodiments, the battery is coin-type, for example 2032 coin cell batteries, 18650 cylindrical cell batteries, pouch cell batteries, and others. In addition to the negative electrode containing CNS-based material (for example as described above), the battery comprises other components, for example, a positive electrode, which is made for example from positive electrode materials based on intercalation chemistry, for example chemical reactions typically involving the transfer of a single electron. Other types of positive electrode materials, which insert lithium ions into for example FeF3, can transfer multiple electrons through a more complex reaction mechanism known as a conversion reaction.

[0108] In other embodiments, the compositions described herein are used (for example, incorporated) in electrodes of other energy storage devices, for example, primary alkaline batteries, primary lithium batteries, nickel metal hydride batteries, sodium batteries, lithium sulfur batteries, lithium air batteries, and supercapacitors. Methods of manufacturing such devices are known in the art and for example described in "Battery Reference Book", TR Crompton, Newness (2000).

[0109] In preferred embodiments according to the application, the battery is prepared by mixing the ingredients of the conductive agent dispersion, active material, binder, solvent, etc. to prepare a positive / negative electrode slurry, and coating the slurry on a current collector to obtain a positive / negative electrode sheet. An electrode assembly is prepared by interposing a separator between the positive electrode sheet and the negative electrode sheet, and then the electrode assembly is placed in a case, and an electrolyte is injected into the case to prepare the battery.

[0110] Thus, finally, in a sixth aspect, the present application also provides a battery, preferably a lithium ion battery, comprising an electrode according to the present application.

[0111] In preferred embodiments according to the application, the battery has a DCIR increase rate of less than or equal to 60% and / or a low temperature discharge capacity retention rate of greater than or equal to 60%.

[0112] In preferred embodiments according to the present application, the DCIR growth rate can be less than or equal to 55%, less than or equal to 50%, less than or equal to 45%, less than or equal to 40%, less than or equal to 35%, less than or equal to 30%, less than or equal to 25%, less than or equal to 20%, less than or equal to 15%, or less than or equal to 10%. For example, the DCIR growth rate can be greater than or equal to 1%, greater than or equal to 2%, greater than or equal to 3%, greater than or equal to 4%, greater than or equal to 5%, greater than or equal to 6%, greater than or equal to 7%, or greater than or equal to 8%.

[0113] For example, the DCIR growth rate can be measured at 1000 cycles at 25 °C. In particular, the DCIR growth rate can be measured as described in the DCIR Growth Rate Test below.

[0114] In preferred embodiments according to the present application, the low temperature discharge capacity retention can be greater than or equal to 65%, greater than or equal to 70%, greater than or equal to 75%, greater than or equal to 80%, greater than or equal to 81%, greater than or equal to 82%, greater than or equal to 83%, greater than or equal to 84%, greater than or equal to 85%, greater than or equal to 86%, greater than or equal to 87%, greater than or equal to 88%, greater than or equal to 89%, greater than or equal to 90%, greater than or equal to 91%, greater than or equal to 92%, or greater than or equal to 93%. For example, the low temperature discharge capacity retention can be less than or equal to 99%, less than or equal to 98%, less than or equal to 97%, less than or equal to 96%, less than or equal to 95%, or less than or equal to 94%.

[0115] For example, the low temperature discharge capacity retention can be the ratio of discharge capacity at -20 °C and 25 °C (-20 °C / 25 °C). In particular, the low temperature discharge capacity retention can be measured as described in the Low Temperature Discharge Capacity Retention Test below.

[0116] A variety of techniques can be used to characterize the electrode compositions, electrodes, and batteries described herein, and / or to confirm the presence of CNS-based materials. Examples include, but are not limited to, electron microscopy such as TEM, SEM, Raman spectroscopy, or other suitable qualitative or quantitative analytical methods.

[0117] Electrode performance and / or properties can be evaluated by procedures known in the art, or adapted or developed techniques. Suitable techniques include, for example, in-plane and thru-plane electrode conductivity, electrochemical impedance spectroscopy (EIS), constant current charge-discharge, hybrid pulse power capability (HPPC), cycling.

[0118] The application is further illustrated by the following non-limiting examples.

[0119] Examples

[0120] The raw materials used in the examples and comparative examples according to the present application are as follows:

[0121] Carbon nanostructure

[0122] Carbon black

[0123] Individualized pristine form of carbon nanotube

[0124] Preparation of conductive agent dispersion

[0125] The respective conductive agent compositions were obtained according to the formulations shown in Table 1 below for each of the examples and comparative examples. Then, the respective conductive agent compositions, hydrogenated nitrile rubber (HNBR), and N-methyl pyrrolidone (NMP) were mixed and dispersed by a homogenizer to obtain a stable dispersion liquid.

[0126] Preparation of positive electrode

[0127] The conductive agent dispersion corresponding to each of the examples and comparative examples, LiNi 0.6 Co 0.2 Mn 0.2 O2, polyvinylidene fluoride (PVDF) were mixed in a weight ratio of 1.2:97.8:1 in N-methyl pyrrolidone (NMP) to prepare a positive electrode slurry, and then coated on an aluminum foil as a positive electrode current collector, after which the solvent was removed.

[0128] Preparation of negative electrode:

[0129] The negative electrode in all of the examples and comparative examples was prepared by mixing carbon black as a conductive agent, graphite as an active material, a styrene butadiene rubber binder, and a carboxymethyl cellulose (CMC) thickener in a weight ratio of 1.2:95.8:1.6:1.4 in water to prepare a negative electrode slurry, and then coating on a copper foil as a negative electrode current collector, after which the solvent was removed.

[0130] Preparation of lithium ion battery:

[0131] A separator was interposed between the positive electrode and the negative electrode prepared above to prepare an electrode assembly, the electrode assembly was placed inside a case, and a 5101A type lithium ion battery electrolyte was injected into the case, thereby preparing a lithium ion battery.

[0132] The present application was subjected to the following tests to embody the technical effect of the conductive agent composition of the present application in the performance improvement of a lithium ion battery.

[0133] Performance test method

[0134] Low temperature discharge capacity retention test

[0135] The lithium ion battery prepared above was charged to 4.25V at 0.5C current at 25°C, then charged at 4.25V until the cutoff current was 0.05C, and discharged to 2.8V at 0.5C current. The discharge capacity at -20°C was measured. Similarly, the discharge capacity at 25°C was measured. The ratio of the discharge capacity at -20°C to that at 25°C (-20°C / 25°C) was calculated to evaluate the low temperature discharge performance.

[0136] Cycle test

[0137] The lithium ion battery prepared above was charged to 4.25V at 0.5C current at 25°C, then charged at 4.25V until the cutoff current was 0.05C, and discharged to 2.8V at 0.5C current. The cycle capacity retention was recorded.

[0138] Cycle process DC internal resistance (DCIR) test:

[0139] At 25°C, after each 100 cycle test, the battery was adjusted to 50% SOC and rested for 10 minutes. It was discharged at 2C current (ΔI) for 10s, and the voltage change (ΔU) data was recorded to complete the discharge DCIR test. The DCIR value was calculated as follows and the DCIR growth rate was derived therefrom to characterize the conductivity.

[0140] DCIR = ΔU / ΔI;

[0141] DCIR growth rate = (DCIR (1000 cycles) / DCIR (initial) - 1)*100%

[0142] The formulations of the examples and comparative examples according to the present application are shown in Table 1 below.

[0143] Table 1: Formulations of the examples and comparative examples according to the present application

[0144] Table 2: Test results of the examples and comparative examples according to the present application

[0145] From the comparison of Examples 1 to 5, and the comparison of Examples 12 and 13 with Examples 14 and 15, it can be seen that, when a carbon black having a specific surface area greater than 200 m 2 / g is used, a lower DCIR growth rate and a higher battery low temperature discharge capacity retention can be achieved, as compared to the use of a carbon black having a specific surface area less than or equal to 200 m 2 / g. In particular, when a carbon black having a specific surface area in the range of 800 m 2 / g to 1600 m2 When the carbon black has a surface energy in the range of 12 to 18 mJ / m

[0146] As can be seen from the comparison of Example 4 with Examples 6 and 7, when CNS is further included in the conductive agent composition, a further improved DCIR increase rate and battery low-temperature discharge capacity retention rate can be achieved.

[0147] As can be seen from the comparison of Example 4 with Examples 8 to 11, when the proportion of CNS in the conductive agent composition is increased, the DCIR increase rate is reduced and the battery low-temperature discharge capacity retention rate is increased. In particular, when the proportion of CNS in the conductive agent composition is in the range of 10 to 65% by weight, a significantly lower DCIR increase rate and a significantly higher battery low-temperature discharge capacity retention rate can be achieved.

[0148] Further, it can be seen that when the carbon black has a surface energy in the range of 12 to 18 mJ / m 2 , preferably 12 to 17 mJ / m 2 , La in the range of 16 to 18 to , and / or Lc in the range of 10 to 10 to , an improved DCIR increase rate and battery low-temperature discharge capacity retention rate can be achieved.

[0149] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. In addition, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms: comprises, comprising, includes, and / or containing, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Furthermore, it will be understood that when an element, including its parts or subsystems, is referred to as being coupled or

[0150] It will be understood that, although the terms "first" and "second" can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Thus, a first element discussed below could be termed a second element, and, similarly, a second element could be termed a first element without departing from the teachings of the present application.

[0151] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0152] While the application has been particularly shown and described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details can be made therein without departing from the scope of the application encompassed by the appended claims.

Claims

1. Electrically conductive agent composition comprising carbon black and at least one material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures and broken multiwall carbon nanotubes, wherein the carbon black has a BET specific surface area of more than 200 m 2 / g, preferably 300 m 2 / g to 2000 m 2 / g, preferably 400 m 2 / g to 1800 m 2 / g, preferably 500 m 2 / g to 1600 m 2 / g, preferably 600 m 2 / g to 1400 m 2 / g, preferably 700 m 2 / g to 1000 m 2 / g, most preferably 800 m 2 / g to 900 m 2 / g or 800 m 2 / g to 1600 m 2 / g, and wherein the carbon nanostructures or fragments of carbon nanostructures comprise a plurality of multiwall carbon nanotubes crosslinked and branched to each other, and wherein the broken multiwall carbon nanotubes are derived from carbon nanostructures and are branched and share common walls to each other.

2. Electrically conductive agent composition according to claim 1, wherein the material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures and broken multiwall carbon nanotubes is present in the electrically conductive agent composition in an amount of 1 to 65 wt.%, based on the total weight of the electrically conductive agent composition.

3. The electrically conductive agent composition of claim 1 or 2, wherein the carbon black has one or more of the following characteristics: (1) a surface energy of no more than 20 mJ / m2 2 ; (2) a La crystallite size of as measured by Raman spectroscopy, and (3) a Lc crystallite size of 4. Electrically conductive agent composition according to any one of claims 1 to 3, further comprising individualized pristine form carbon nanotubes.

5. The electrically conductive agent composition of claim 4, wherein the carbon nanotubes further comprise at least one selected from the group consisting of single-walled carbon nanotubes, oligowalled carbon nanotubes, and multi-walled carbon nanotubes, preferably the carbon nanotubes have a BET specific surface area of 1500 m2 / g or less. 2 / g or less.

6. Electrically conductive agent composition according to any one of claims 1 to 5, wherein: at least one of the carbon nanostructures, fragments of carbon nanostructures and broken multiwall carbon nanotubes has a length equal to or greater than 2 micrometers, as determined by SEM, at least one of the carbon nanostructures, fragments of carbon nanostructures and broken multiwall carbon nanotubes has an aspect ratio of length to diameter in the range of 200-1000, along a 2 micrometers length of at least one of the carbon nanostructures, fragments of carbon nanostructures and broken multiwall carbon nanotubes, there are at least two branches, as determined by SEM, at least one of the carbon nanostructures, fragments of carbon nanostructures and broken multiwall carbon nanotubes exhibits asymmetry with respect to the number of walls observed in the region after a branching point, with respect to the region before the branching point, and / or there is no catalyst particle present at or near the branching point, as determined by TEM.

7. Electrically conductive agent composition according to any one of claims 1 to 6, wherein the at least one material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures and broken multiwall carbon nanotubes comprises 2-30 coaxial nanotubes, as determined by TEM at a magnification sufficient to count the number of walls.

8. Electrically conductive agent composition according to any one of claims 1 to 7, wherein at least 1% of the at least one material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures and broken multiwall carbon nanotubes has a length equal to or greater than 2 micrometers, as determined by SEM, an aspect ratio of length to diameter in the range of 200-1000, and / or exhibits asymmetry with respect to the number of walls observed in the region after a branching point, with respect to the region before the branching point.

9. Electrically conductive agent dispersion comprising the electrically conductive agent composition according to any one of claims 1 to 8 and a solvent.

10. The electrically conductive agent dispersion according to claim 9, further comprising a dispersant, preferably the dispersant is selected from the group consisting of polyvinylpyrrolidone, polyacrylamide, polycarboxylic acid, polyacrylic acid, polycarboxylate, polyacrylate, polyvinyl alcohol, montan wax, polyvinyl butyral, nitrile rubber, carboxymethyl cellulose, hydroxyethyl cellulose, polyethylene glycol, polyvinyl acetate, polystyrene sulfonate, polymethacrylate, polyvinyl imine, polyvinyl amine, polypropylene amine, polyacrylonitrile, poly(2-vinylpyridine), block copolyether, cellulose acetate, polyamide, polyimide, hydrogenated nitrile rubber, styrene-maleic anhydride copolymer, polyether sulfone, hydroxymethyl cellulose, chitosan, (hydroxy)ethyl cellulose, methyl cellulose, polyurethane, polyvinylidene fluoride, cellulose ether, silane coupling agent, polyoxyethylene ether, sodium lignosulfonate, derivatives of the above polymers, and combinations thereof; preferably polyvinylpyrrolidone, polyacrylamide, polyacrylic acid, polyacrylate, montan wax, carboxymethyl cellulose, hydroxyethyl cellulose, polyethylene glycol, polyvinyl acetate, polyvinyl amine, polypropylene amine, polyacrylonitrile, poly(2-vinylpyridine), hydrogenated nitrile rubber, and styrene-maleic anhydride copolymer; in particular hydrogenated nitrile rubber.

11. The electrically conductive agent dispersion according to claim 9 or 10, further comprising a wetting agent, the wetting agent has a carbon atom number of 2 to 16, a boiling point of not more than 200 °C at standard atmospheric pressure, a surface tension of not more than 50 mN / m at 25 °C, and is preferably selected from the group consisting of alcohol compounds, amine compounds, alcohol amine compounds, ether compounds, ester compounds, nitrile compounds, alkane compounds, siloxane compounds, and a molecular structure comprising at least one of the following functional groups: hydroxyl group, primary amino group, secondary amino group, tertiary amino group, nitrile group, carbonyl group, ester group, anhydride group, ether bond, amide bond, urethane bond, siloxane bond.

12. The electrically conductive agent dispersion according to claim 9 or 10, wherein the solvent is selected from the group consisting of N-methylpyrrolidone, water, methanol, ethanol, n-propanol, isopropanol, acetone, butanol, butanediol, pentane, n-hexane, cyclohexane, trichloroethane, carbon tetrachloride, ethyl acetate, methyl ethyl ketone, dimethylformamide, dimethylacetamide, benzene, xylene, dipropylene glycol methyl ether, tripropylene glycol methyl ether, dimethyl sulfoxide, dihydrolevogluside, and combinations thereof.

13. A method of making the electrically conductive agent dispersion according to any one of claims 9 to 12, comprising combining the electrically conductive agent composition, a solvent, and optionally a dispersant to form a dispersion.

14. Use of the electrically conductive agent composition according to any one of claims 1 to 8 or the electrically conductive agent dispersion according to any one of claims 9 to 12 for manufacturing an electrode.

15. An electrode, preferably for a lithium ion battery, comprising a current collector and an electrode active material layer, wherein the electrode active material layer comprises the electrically conductive agent composition according to any one of claims 1 to 8.

16. A battery, preferably a lithium ion battery, comprising the electrode according to claim 15.

17. The battery of claim 16, wherein the battery has a DCIR increase rate of less than or equal to 60% and / or a low-temperature discharge capacity retention rate of greater than or equal to 60%.

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